Chapter 1 section 3 Chemical Compounds
Elements- any substance that cannot be broken down into simpler substances.
The 6 six basic elements of living organisms are Carbon, Hydrogen, Oxygen, Nitrogen,
Sulfur, and Phosphorus.
Compound- two or more elements chemically combined
Organic compound- a compound containing the element Carbon. The four main types are
Carbohydrates, Lipids, Proteins, and Nucleic Acids.
Inorganic compounds- a compound that does not contain Carbon such as Water (H2O) and
Sodium Chloride (NaCl)
Carbohydrate- an organic rich molecule. There are 2 forms, simple carbs which are sugars
(monosaccharides) and made of only one molecule and complex carbs are two or more molecules in
chains (polysaccharides). The main function of a carbohydrate is as the primary energy source for
organisms. Plants can use them as structure (cellulose). Monomers are monosaccharides
Lipids- organic rich compounds such as fats (animals), oils (plants), and waxes. The two main jobs of
lipids are for energy storage and the creation of membranes (phospholipids). Also used for insulation and
protection. Monomers are fatty acids.
Proteins- large organic molecules created from long chains of amino acids. There are 20 common amino
acids used to create proteins. The amino acids that your body cannot make are called essential amino
acids, and you must get them all in your diet. Proteins are used for everything from pigments to enzymes
to muscle fibers to bone structures, etc etc Monomers are amino acids.
Enzyme- a protein that speeds up chemical reactions in living organisms.
Nucleic Acids- Very long organic molecules. Two types DNA(your heredity, found only in the nucleus of
eukaryotic cells, the nucleoid of prokaryotic cells) and RNA(the pattern for protein synthesis; found in the
nucleus and the cytoplasm). Coiled tightly = chromosomes, loose and stringy = chromatin. Monomers
are nucleotides.
Water is important to all cells. 1. Almost all chemical reactions use water. 2. Water provides support and
shape for the cell. 3. Water helps regulate the temperature of the cell.
Section 4 The Cell and Its Environment
Selectively Permeable- allows certain materials to move freely across a membrane.
Diffusion- the movement of small molecules across a membrane from an area of high concentration to an
area of low concentration without the use energy until it reaches the state of Equilibrium (down the
concentration gradient).
Osmosis- the diffusion of water across a membrane from an area of high to low without the use energy
until it reaches the state of Equilibrium (down the concentration gradient).
Hyoptonic solutions have a higher water concentration outside the cell than inside, water moves into the
cell and the cell can swell and eventually burst.
Hypertonic solutions have higher water concentrations inside the cell than outside, water moves out of the
cell and the cell shrivels
Isotonic solutions have equal water concentrations on both sides of the membrane. Water moves into
and out of the cell at the same rate, and the cell stays the same size.
Passive Transport- Movement of molecules from high concentration to low concentration without the use
of energy. Diffusion and Osmosis are examples of Passive Transport.
Active Transport- the movement of materials through a cell membrane via protein doorways that requires
the use of energy to go from area of low concentration to an area of high concentration (against the
concentration gradient).
Transport Proteins- doorways in the membrane that pick up materials and move them inside the
cell with the use of energy.
Engulfing- the cell membrane surrounds or encloses a particle forming a vacuole or vesicle.
Endocytosis – taking large particles in through engulfing. Two types:
Phagocytosis – Taking in solids
Pinocytosis – Taking in liquids
Exocytosis – Removing large particles from the cell, opposite of endocytosis.
Why are cells so small? Due to the surface to volume ratio, a cell can take in more material than it can
actually hold and would eventually cause the cell to burst. Also if they were not small, it would take too
long to transport materials across the cell.